Field of the Invention
Embodiments of the present invention generally relate to a method of coating components of a plasma processing chamber, more specifically, to a method of coating an electro-static chuck assembly.
Description of the Related Art
Semiconductor processing involves a number of different chemical and physical processes whereby minute integrated circuits are created on a substrate. Layers of materials which make up the integrated circuit are created by chemical vapor deposition, physical vapor deposition, epitaxial growth, and the like. Some of the layers of material are patterned using photoresist masks and wet or dry etching techniques. The substrate utilized to form integrated circuits may be silicon, gallium arsenide, indium phosphide, glass, or other appropriate material.
A typical semiconductor processing chamber includes a chamber body defining a process zone, a gas distribution assembly adapted to supply a gas from a gas supply into the process zone, a gas energizer, e.g., a plasma generator, utilized to energize the process gas to process a substrate positioned on a substrate support assembly, and a gas exhaust. The substrate support assembly may include an electro-static chuck assembly that holds the substrate to the substrate support assembly during processing. During plasma processing, the energized gas is often comprised of highly corrosive species which etches and erodes exposed portions of the substrate support assembly. One example of a plasma process is an in-situ chamber cleaning process, in which the substrate support assembly is exposed to the highly corrosive species. To avoid inconsistent or undesirable process results, due to erosion induced variations in the electrical properties of the electro-static chuck, the support substrate assembly is replaced after a number of process cycles. The replacement of the substrate support assembly with a new assembly can be very costly from a material cost and machine down time perspective. Additionally, the erosion of the substrate support assembly may generate particles that can contaminate substrates being held on the substrate support assembly, thereby resulting in processing defects.
To protect the substrate support assembly from the corrosive species, a coating material may be applied to the substrate support assembly when the substrate support assembly is new and during refurbishment processes, which are performed after the substrate support assembly has been integrated into an electro-static chuck and used in a processing chamber for a period of time. Typically, the coating process is performed at an elevated temperature.
A typical substrate support assembly, such as an electro-static chuck assembly, may contain multiple components, which are bonded together by a bonding material. However, the typical bonding materials used to thermally and/or mechanically couple the various components together can degrade, outgas or change chemically or mechanically at the typical temperatures used to coat these substrate support assembly components. Therefore, the bonding materials can place limitations on the refurbishment process used to prepare a substrate support assembly for reuse, especially when the processes are performed at elevated temperatures. Therefore, there is a need for an improved method of coating substrate support components contained in an assembly, such as an electrostatic chuck assembly.